Analysts noting that we shouldn't pay too much attention to one month's worth of performance has become almost a cliché these days, but the advice still holds true.

At Baseball America, we don't put too much stock into any one month's numbers, whether those numbers come in April or August.

The statistics are a record of what the player has done on the field, and while we can use that sample data to estimate a player's true talent level, we need a larger sample of information to make a reliable estimate.

The heart of player evaluation at the minor league level is in scouting, with large samples of performance information used to supplement the scouting reports. A few balls sneaking past an infielder, a few games against below-average pitchers, and a player can see his numbers inflated over the course of a month, making it imperative to look at the underlying skills and tools in a player's possession.

Small sample size or not, certain players have improved their stocks since the beginning of the season. If there are reasons why the player's performance has improved—a few extra ticks of velocity on the fastball, an improved changeup, better health and conditioning, the elimination of extraneous movement for a swing or a pitching delivery—that could signify real change.

Performance grabs our initial attention, but the scouting reports might tell us more about whether a player has made true, sustainable improvement. Plenty of players have seen their stock rise or fall this season that are not included in this report. Here's a look at five players who missed the Baseball America Top 100 list who have some helium going forward after their strong starts.

Trevor Cahill, rhp, Athletics

Putting up a 1.80 ERA through five starts with a 39-5 K-BB ratio in 30 innings would be impressive in any league. Doing it in the high run scoring environment of the high Class A California League as Cahill has done this season is even more impressive, especially considering he is the league's third-youngest pitcher at 20 years old.

"He has a devastating sinker that's natural for him," A's director of player personnel Billy Owens said. "It's in the low-90s, gets a lot of groundballs. It's unusual in that he's a ground ball guy but he can also get strikeouts with his knuckle-curve and his slider. He lengthened his arm this year, so he's throwing four-seam fastballs now more than last year, and he tops out at 93 (mph)."

Owens said that Cahill had some natural sinking movement on his fastball when area scout Craig Weissmann signed him out of a San Diego high school, but Owens credited the A's player development staff for helping Cahill improve the quality of the pitch even further. Wiseman signed Cahill in 2006 in the second round, as Cahill fell into their laps after his velocity dropped as a high school senior due to illness.

In his first full professional season last year, Cahill had a 2.73 ERA, 117 strikeouts and 40 walks in 1051⁄3 innings last year for low Class A Kane County. Cahill's fastball sits in the low 90s with the potential for more velocity out of his 6-foot-3, 211-pound frame. He also has an outstanding curveball and an improving changeup.

"He was as good as anyone in the Midwest League last year, especially considering his age, so he's just continuing that trend," Owens said. "He's got good control; he's shown that throughout his minor league career."

Brandon Erbe, rhp, Orioles

Erbe struggled last year with his command and with allowing runs, posting a 6.26 ERA in 1191⁄3 innings with 62 walks (4.7 per nine innings). No starter in the high Class A Carolina League allowed more runs than Erbe, and just two pitchers walked more batters.

Despite Erbe's struggles, there were plenty of promising signs for the 2005 third-rounder. For one, Erbe was only 19 years old last season, making him the league's youngest pitcher. Despite his youth, Erbe still had 111 strikeouts (8.4 per nine innings) and had the underlying stuff that made him the No. 2 prospect in the organization heading into the season—a mid-90s fastball, a slider with plus potential and an improving changeup.

Part of the adversity that Erbe faced last season wasn't a simple matter of playing against older competition. Erbe struggled to repeat his delivery, which in turn led to his control problems. Erbe is back for another season with Frederick, where he has smoothed out his leg kick, improved the landing in his delivery reduced his head movement, according to manager Tommy Thompson.

"When you're making an adjustment it's easy to see a problem," Thompson said. "To fix it is tough. There is a lot of video work and windup and delivery mechanics on a dry mound."

So far, so good for Erbe, who through five games had a 2.73 ERA and a 27-6 K-BB ratio in 292⁄3 innings, working at 92-95 mph with his fastball early in the season. And for all his Carolina League experience, Erbe is still the third-youngest pitcher in the league.

"He has a chance to get better real quick," Thompson said. "He was a prospect for me last year and is even more this year."

Jeremy Hellickson, rhp, Rays

Baseball America ranked Hellickson the No. 1 prospect in the short-season New York-Penn League in 2006 after Hellickson had a 2.43 ERA with a 96-16 K-BB ratio in 772⁄3 innings as an 18-year-old. The following season, however, Hellickson struggled with his conditioning coming into spring training, according to Rays pitching coordinator Dick Bosman.

The Rays held him back that year, not letting him make his first minor league start until April 24. He had a solid campaign, posting a 2.67 ERA with a 106-34 K-BB ratio in 1111⁄3 innings, showing a low-90s fastball that touched 95 mph, a good feel for his curve and an excellent feel for pitching.

This year, Hellickson has wasted no time getting off to a fast start for high Class A Vero Beach. Lefthander David Price, the No. 1 pick in last year's draft, was supposed to be the ace of the staff. But with Price out injured, Hellickson put together the best April of any elite pitching prospect in 2008.

Through five games, Hellickson had a 0.93 ERA and a ridiculous 41-2 K-BB ratio in 29 innings. Hellickson has snuck a bit under the radar in an organization with the top-ranked farm system in baseball replete with high-end pitching talent, but he could become more of a household name if the rest of his 2008 season comes anywhere near his April performance.

Mike Saunders, cf, Mariners

Saunders hit well last season—.299/.392/.473 in 507 plate appearances with high Class A High Desert—but those numbers were also somewhat aided by playing in the hitter-friendly California League.

Perhaps last year was Saunders' breakout year, but this season could get Saunders more attention as he turns his premium athletic ability and tools into more refined baseball ability. Through 24 games with Double-A West Tenn, Saunders was off to a .292/.382/.461 start through 94 plate appearances. It's not much to go on, but it's a promising start for Saunders, although his 24 strikeouts highlight contact problems that he has had since the Canadian native signed as a draft-and-follow as a 2004 11th-rounder.

As Saunders grows into his 6-foot-4, 215-pound frame, he may end up having to move to a corner outfield position, but for now he's a capable center fielder with above-average speed. With his body and the loft he generates with his swing, Saunders has a good chance to tap into his power potential.

"He's a big kid who's got some power and some speed," said a pro scout with a National League organization. "He's going to get bigger, so he has a chance to develop more power, which means he'll probably lose a step, but he's got good instincts out there."

Daryl Thompson, rhp, Reds

The 22-year-old Thompson missed the cut for the Prospect Handbook this year, but he's a virtual lock to make the 2009 edition if the Reds keep in down on the farm. Through his first five games with Double-A Chattanooga, Thompson had a 0.57 ERA with a 36-4 K-BB ratio in 311⁄3 innings.

"He could pitch in the big leagues right now," said one scout. "He's up to 94 and he maintained his velocity through eight innings. He changed speeds on his breaking ball and showed good command with a simple delivery that he repeats well. There's a lot of deception there. He's definitely a fast track guy if (the Reds) need pitching by the end of the season."

New Reds general manager Walt Jocketty will be the one in charge of deciding how the Reds will handle Thompson's rise through the organization. It was recently fired GM Wayne Krivsky who acquired Thompson, though, midway through the 2006 season. In a trade widely derided both at the time and in the present, the Reds traded for Thompson, lefty Bill Bray, righty Gary Majewski and shortstops Royce Clayton and Brendan Harris in exchange for outfielder Austin Kearns, shortstop Felipe Lopez and righthander Ryan Wagner.

Last year Thompson had a 0.96 ERA and a 24-2 K-BB ratio with low Class A Dayton. Upon a promotion to high Class A Sarasota, Thompson had a 3.77 ERA with a 97-31 K-BB ratio. Thompson has always been a consistent strike-thrower since signing with the Expos as an eighth-rounder in 2003, averaging 2.7 walks per nine innings in 356 innings from 2003-2007.

Despite the success, there is a significant red flag, one that scouts surely are aware of but can't see with their eyes when Thompson is blowing hitters away on the mound. Thompson was limited to 202⁄3 innings in 2005 recovering from surgery on the labrum in his right shoulder. While Thompson's early results in his comeback from labrum surgery are promising and his mechanics seem solid, his medical history makes him an increased risk for injury, as the list of pitching prospects who have returned from the procedure is not a long one.

"It looks like he's back, he has the loose arm," the scout said. "The arm action, the live, athletic body, the mechanics are all good. I've got no reason to predict future arm problems."

Contributing: Nathan Rode

QUICK HITS

• Cardinals reliever Chris Perez ranked second in the Cardinals system, behind only center fielder Colby Rasmus. The 6-foot-4, 225-pound righthander had a 2.31 ERA through 112⁄3 innings in 12 appearances this year for Triple-A Memphis, where he has 12 strikeouts and four walks.

Perez's main weapons are a 93-95 mph fastball and a mid-80s slider with late bite. He still has to sort out issues with his command after walking 41 batters in 55 innings between Memphis and Double-A Springfield last season.

"Perez has got a great arm," said a scout who watched him pitch this season. "His command is going to be a problem. He never has gotten that slider near the hitting zone to set up the hitter, so he's got some work to do."

• Another reliever with past control problems, Red Sox righthander Daniel Bard, has caught the attention of some scouts this season. Bard was the 28th overall pick in 2006 out of North Carolina. But a 7.08 ERA and a K-BB ratio that looked like a typo—47-78 in 75 innings between low Class A Greenville and high Class A Lancaster—made his debut season a disappointment.

The Red Sox moved Bard to the bullpen, and the results have been dramatically different. Bard, 22, is old for low Class A, but he hadn't allowed a run in 18 innings, allowing just six hits with a 27-3 K-BB ratio. Bard, whose fastball has touched 100 mph, has pitched mostly in two-inning stints for Greenville.

"His command is a lot better than what it has been," a scout said. "He doesn't look anything like he did last year."

• After starting the season with a six-game hitting streak and hitting .297/.458/.514 in his first 12 games, Marlins outfielder Cameron Maybin slumped considerably, dropping down to .214/.365/.369 in 24 games. Maybin also has 36 strikeouts, looking particularly vulnerable against changeups.

"He looked confused to the point where he lost some of his aggressiveness," said an AL scout. "But he has excellent bat speed, it's not a long swing. I think he'll hit. He might be struggling right now, but you're going to watch him catch up with the league at least in the second half."